Auto-ban bad user names

[alfetopito]

Summary

The bot should monitor and auto-ban users with usernames that are clearly intent to scam people

The bot should monitor:

1. Users joining the server
2. Users changing their names
3. Users changing their nicknames (I know, but it's different)

Notes

For 1, watch for the guildMemberAdd event
For 2, watch for the guildMemberUpdate event
For 3, watch for the userUpdate event